Scientists have created a genetically modified plant that turns red in the presence of buried explosives, an ideal tracker for pinpointing land mines.
But the discovery has sparked a row among activists and charities. Some claim the system is dangerous, unproven and unnecessary. Others say it could prove vital in dealing with the world’s land mines, which kill and maim thousands of people every year.
”We are really excited about this, even though it is early days,” said Simon Oestergaard, chief executive of Aresa Biodetection, the Danish company developing the plant project. ”It has considerable potential.”
The detectors were originally developed by Carsten Meier of the University of Copenhagen and are based on thale cress, Arabidopsis thaliana. His team added a gene to the plant’s DNA causing its green leaves to turn red in the presence of nitrogen dioxide, a gas given off by underground mines. The leaves change colour three to five weeks after being planted.
The scientists created their tracker cress by manipulating genes that make leaves turn red in autumn. The pigment, anthocyanin, is normally turned off during the growing season, but the researchers inserted a gene that turns on this colour-making process in the presence of nitrogen dioxide.
The plant could thus provide tell-tale evidence that explosives are buried underground. The only problem is that sowing the seeds could set off mines, but Aresa is developing a spray gun that will allow workers to spread a mixture of slurry and seed over affected areas, probably from low-flying aircraft. A few weeks after spraying, splodges of vegetation would reveal the presence of mines.
The system would only pinpoint explosives in shallow soil, but as most devices are just under the surface this is not a major problem. Meier’s team has also removed important growth hormone genes from their tracker plant so that it cannot spread into the wild without being treated with special fertiliser.
However, other groups criticised the project because it would make arid areas attractive to local livestock, which — along with their human minders — might wander over mined land they would otherwise have avoided.
And there are other criticisms.
”These crops will not take root on land already covered with vegetation, as is the case with much land-mined ground,” said Sean Sutton, of charity organisation the Mines Advisory Group. ”That will limit their use. Also many mines are sealed in plastic cases that will not let nitrogen dioxide seep out. The GM cress would remain green, but there would still be mines underneath.” — Guardian Unlimited Â